Test-Fix-Test Data Reference Example: Difference between revisions

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The book has the following results:
The book has the following results:


Beta = 0.413, Lambda = 1.769
*Beta = 0.413, Lambda = 1.769


DMTBF = 52.7
*DMTBF = 52.7


Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)
*Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)





Revision as of 15:51, 13 June 2014

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RGA_Reference_Examples

This example compares the results for test-fix-test data (time terminated).


Reference Case

Crow, L.H., Confidence Interval Procedures for the Weibull Process with Applications to Reliability Growth, U.S. Army Material Systems Analysis Activity, 1981.


Data

The following table shows the data.

0.2
4.2
4.5
5
5.4
6.1
7.9
14.8
19.2
48.6
85.8
108.9
127.2
129.8
150.1
159.7
227.4
244.7
262.7
315.3
329.6
404.3
486.2
Termination Time = 500 hours


Result

The book has the following results:

  • Beta = 0.413, Lambda = 1.769
  • DMTBF = 52.7
  • Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)


Results in RGA


[math]\displaystyle{ \begin{align} \widehat{\beta }=&\frac{N}{{N\ln T^{*}}-\sum_{i=1}^{N}T_{i}}\\ \\ =&\frac{23}{{23\cdot \ln \left ( 500 \right )}-87.2106}\\ \\ =&0.4127 \end{align}\,\! }[/math]


[math]\displaystyle{ \begin{align} \widehat{\lambda }=&\frac{N}{T^{*\beta }}\\ \\ =&\frac{23}{500^{0.4127}}\\ \\ =&1.7691 \end{align}\,\! }[/math]


CB for Weibull Results.png


CB for Weibull QPC.png